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Author |
Bennett, J.J.; Buldgen, G.; de Salas, P.F.; Drewes, M.; Gariazzo, S.; Pastor, S.; Wong, Y.Y.Y. |
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Title |
Towards a precision calculation of the effective number of neutrinos N-eff in the Standard Model. Part II. Neutrino decoupling in the presence of flavour oscillations and finite-temperature QED |
Type |
Journal Article |
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Year |
2021 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
04 |
Issue |
4 |
Pages |
073 - 33pp |
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Keywords |
cosmological neutrinos; neutrino properties; particle physics – cosmology connection; physics of the early universe |
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Abstract |
We present in this work a new calculation of the standard-model benchmark value for the effective number of neutrinos, N-eff(SM), that quantifies the cosmological neutrinoto-photon energy densities. The calculation takes into account neutrino flavour oscillations, finite-temperature effects in the quantum electrodynamics plasma to O(e(3)), where e is the elementary electric charge, and a full evaluation of the neutrino-neutrino collision integral. We provide furthermore a detailed assessment of the uncertainties in the benchmark N(eff)(SM )value, through testing the value's dependence on (i) optional approximate modelling of the weak collision integrals, (ii) measurement errors in the physical parameters of the weak sector, and (iii) numerical convergence, particularly in relation to momentum discretisation. Our new, recommended standard-model benchmark is N-eff(SM) 3.0440 +/- 0.0002, where the nominal uncertainty is attributed predominantly to errors incurred in the numerical solution procedure (vertical bar delta N-eff vertical bar similar to 10(-4)), augmented by measurement errors in the solar mixing angle sin(2) theta(12) (vertical bar delta N-eff vertical bar similar to 10(-4)). |
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Address |
[Bennett, Jack J.; Wong, Yvonne Y. Y.] Univ New South Wales, Sch Phys, Sydney Consortium Particle Phys & Cosmol, Sydney, NSW 2052, Australia, Email: j.j.bennett@unsw.edu.au; |
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Publisher |
Iop Publishing Ltd |
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English |
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ISSN |
1475-7516 |
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Conference |
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Notes |
WOS:000647827600001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4827 |
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Permanent link to this record |
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Author |
Di Valentino, E.; Gariazzo, S.; Mena, O. |
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Title |
Most constraining cosmological neutrino mass bounds |
Type |
Journal Article |
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Year |
2021 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
104 |
Issue |
8 |
Pages |
083504 - 7pp |
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Keywords |
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Abstract |
We present here up-to-date neutrino mass limits exploiting the most recent cosmological data sets. By making use of the cosmic microwave background temperature fluctuation and polarization measurements, supernovae Ia luminosity distances, baryon acoustic oscillation observations and determinations of the growth rate parameter, we are able to set the most constraining bound to date, Sigma m(v) < 0.09 eV at 95% C.L. This very tight limit is obtained without the assumption of any prior on the value of the Hubble constant and highly compromises the viability of the inverted mass ordering as the underlying neutrino mass pattern in nature. The results obtained here further strengthen the case for very large multitracer spectroscopic surveys as unique laboratories for cosmological relics, such as neutrinos: that would be the case of the Dark Energy Spectroscopic Instrument survey and of the Euclid mission. |
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Address |
[Di Valentino, Eleonora] Univ Durham, Inst Particle Phys Phenomenol, Dept Phys, Durham DH1 3LE, England, Email: eleonora.di-valentino@durham.ac.uk; |
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Amer Physical Soc |
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English |
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ISSN |
2470-0010 |
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Conference |
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Notes |
WOS:000704632300010 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4996 |
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Author |
Lopez-Ibañez, M.L.; Melis, A.; Jay Perez, M.; Rahat, M.H.; Vives, O. |
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Title |
Constraining low-scale flavor models with (g-2)(mu) and lepton flavor violation |
Type |
Journal Article |
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Year |
2022 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
105 |
Issue |
3 |
Pages |
035021 - 21pp |
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Keywords |
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Abstract |
We present here two concrete examples of models where a sub-TeV scale breaking of their respective T-13 and A(5) flavor symmetries is able to account for the recently observed discrepancy in the muon anomalous magnetic moment, (g – 2)(mu). Similarities in the flavor structures of the charged-lepton Yukawa matrix and dipole matrix yielding (g – 2)(mu) give rise to strong constraints on low-scale flavor models when bounds from lepton flavor violation (LFV) are imposed. These constraints place stringent limits on the off- diagonal Yukawa structure, suggesting a mostly (quasi)diagonal texture for models with a low flavor breaking scale A(f). We argue that many of the popular flavor models in the literature designed to explain the fermion masses and mixings are not suitable for reproducing the observed discrepancy in (g – 2)(mu), which requires a delicate balance of maintaining a low flavor scale while simultaneously satisfying strong LFV constraints. |
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Address |
[Lopez-Ibanez, M. L.] Chinese Acad Sci, Inst Theoret Phys, CAS Key Lab Theoret Phys, Beijing 100190, Peoples R China, Email: maloi2@uv.es; |
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Publisher |
Amer Physical Soc |
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English |
Summary Language |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2470-0010 |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000767363800008 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5167 |
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Permanent link to this record |
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Author |
Ramalho, M.; Suhonen, J.; Kostensalo, J.; Alcala, G.A.; Algora, A.; Fallot, M.; Porta, A.; Zakari-Issoufou, A.A. |
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Title |
Analysis of the total beta-electron spectrum of( 92)Rb: Implications for the reactor flux anomalies |
Type |
Journal Article |
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Year |
2022 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
106 |
Issue |
2 |
Pages |
024315 - 7pp |
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Keywords |
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Abstract |
We present here a microscopic nuclear-structure calculation of a beta-electron spectrum including all the beta-decay branches of a high Q-value reactor fission product contributing significantly to the reactor antineutrino energy spectrum. We perform large-scale nuclear shell-model calculations of the total electron spectrum for the beta(-) decay of Rb-92 to states in Sr-92 using a computer cluster. We exploit the beta-branching data of a recent total absorption gamma-ray spectroscopy (TAGS) measurement to determine the effective values of the weak axial-vector coupling, g(A), and the weak axial charge, g(A)(gamma(5)). By using the TAGS data we avoid the bias stemming from the pandemonium effect which is a systematic error biasing the usual beta-decay measurements. We take fully into account all the involved allowed and forbidden beta transitions, in particular the first-forbidden nonunique ones which have earlier been shown to be relevant in the context of the reactor-antineutrino flux anomaly and the unexplained spectral shoulder, the “bump,” the former one having been interpreted as one of the strongest evidence for the existence of sterile neutrinos. Here we are able to present quantitative evidence for the relevance of forbidden nonunique beta(-) decays in a total beta spectrum of a fission product, in this case( 92)Rb, which is one of the major contributors to the total reactor antineutrino spectral shape. We demonstrate that taking the forbidden spectral shapes fully into consideration leads for Rb-92 to a 2.6%-4.6% reduction in the expected inverse beta-decay rate at the reactor antineutrino telescopes. We also confirm by our calculation of a total beta-electron spectrum that the forbidden transitions can contribute to the formation of the spectral bump in the reactor-antineutrino flux profile. |
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Address |
[Ramalho, M.; Suhonen, J.] Univ Jyvaskyla, Dept Phys, POB 35, FI-40014 Jyvaskyla, Finland, Email: madeoliv@jyu.fi; |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9985 |
ISBN |
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Expedition |
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Conference |
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Notes |
WOS:000889134200002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5429 |
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Permanent link to this record |
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Author |
NEXT Collaboration (Henriques, C.A.O. et al); Benlloch-Rodriguez, J.M.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Kekic, M.; Lopez-March, N.; Martin-Albo, J.; Martinez, A.; Martinez-Lema, G.; Martinez-Vara, M.; Muñoz Vidal, J.; Novella, P.; Palmeiro, B.; Querol, M.; Renner, J.; Romo-Luque, C.; Sorel, M.; Uson, A.; Yahlali, N. |
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Title |
Neutral Bremsstrahlung Emission in Xenon Unveiled |
Type |
Journal Article |
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Year |
2022 |
Publication |
Physical Review X |
Abbreviated Journal |
Phys. Rev. X |
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Volume |
12 |
Issue |
2 |
Pages |
021005 - 23pp |
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Keywords |
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Abstract |
We present evidence of non-excimer-based secondary scintillation in gaseous xenon, obtained using both the NEXT-White time projection chamber (TPC) and a dedicated setup. Detailed comparison with first-principle calculations allows us to assign this scintillation mechanism to neutral bremsstrahlung (NBrS), a process that is postulated to exist in xenon that has been largely overlooked. For photon emission below 1000 nm, the NBrS yield increases from about 10(-2) photon/e(-) cm(-1) bar(-1) at pressure-reduced electric field values of 50 V cm(-1) bar(-1) to above 3 x 10(-1) photon/e(-) cm(-1) bar(-1) at 500 V cm(-1) bar(-1). Above 1.5 kV cm(-1) bar(-1), values that are typically employed for electroluminescence, it is estimated that NBrS is present with an intensity around 1 photon/e(-) cm(-1) bar(-1), which is about 2 orders of magnitude lower than conventional, excimer-based electroluminescence. Despite being fainter than its excimeric counterpart, our calculations reveal that NBrS causes luminous backgrounds that can interfere, in either gas or liquid phase, with the ability to distinguish and/or to precisely measure low primary-scintillation signals (S1). In particular, we show this to be the case in the "buffer region, where keeping the electric field below the electroluminescence threshold does not suffice to extinguish secondary scintillation. The electric field leakage in this region should be mitigated to avoid intolerable levels of NBrS emission. Furthermore, we show that this new source of light emission opens up a viable path toward obtaining S2 signals for discrimination purposes in future single-phase liquid TPCs for neutrino and dark matter physics, with estimated yields up to 20-50 photons/e(-) cm(-1). |
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Address |
[Henriques, C. A. O.; Teixeira, J. M. R.; Monteiro, C. M. B.; Fernandes, A. F. M.; Fernandes, L. M. P.; Freitas, E. D. C.; dos Santos, J. M. F.] Univ Coimbra, Dept Phys, ILIBPhys, Rua Larga, P-3004516 Coimbra, Portugal, Email: henriques@uc.pt; |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2160-3308 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000792590100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5220 |
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Permanent link to this record |